This started all of a sudden. Tried to start my mechanical 6V92 and it spins over fine but no start. Upon investigation I found the shut off lever does not travel to RUN position when the key is turned on . Mine has a remote air cylinder with a cable connected to the lever. Air cylinder releases, cable is slack, but lever does not move. Is there suppose to be a spring connected to the lever to move it to RUN position. There is not much room there to see and my back doesn't want to let me contort myself enough to see what's going on.
TOM
You just need some lubrication in the system. Just like air tools. I've seen where bus owners will install an oiler on the air line.
The air system is not the culprit. It's working as designed. The cylinder exhausts and the cable is completely slack. The lever itself does not move.
I am going to inject some Marvel Mystery Oil in the air system though. I have some valves at the front that are slow.
TOM
I've seen the lever seize up. It's just a steel rod through the bare aluminum cover of the governor, and corrosion comes easy. Get some lube in and work it, or better take the cover off and free it up on the bench.
Okay-- the stop lever goes into a fork in the governor. If it is getting stuck, you may have something worn out.
That lever is spring loaded by a spring under the cover could be it broke or jumped out of place
Quote from: luvrbus on November 10, 2017, 04:57:54 AM
That lever is spring loaded by a spring under the cover could be it broke or jumped out of place
I looked at it again and found if I pull the lever towards the shut off position AFTER the air cylinder releases (cable is slack at the lever) I hear a very faint click and the lever moves by itself to the RUN position. Gotta be something internal. I really hate to have to take all the insulation off the exhaust pipes to get to it too. It's all original and looks good!
TOM
Out of curiosity, how and where do you intentionally add oil to the air system. Makes sense. I have an issue with my shutoff air solenoid too. It's finicky, usually after a goo 2-3 hour run it won't want to shutoff. All it takes is a tap on the solenoid for it to popout.
Quote from: neoneddy on November 10, 2017, 09:53:18 AM
Out of curiosity, how and where do you intentionally add oil to the air system. Makes sense. I have an issue with my shutoff air solenoid too. It's finicky, usually after a goo 2-3 hour run it won't want to shutoff. All it takes is a tap on the solenoid for it to popout.
i just take the hose off the clamping cylinder and put a small squirt of light oil in it directly...
i am not sure every part of the air system likes oil...
on second thought, yes, i am sure.
Quote from: eagle19952 on November 10, 2017, 11:18:04 AM
i just take the hose off the clamping cylinder and put a small squirt of light oil in it directly...
i am not sure every part of the air system likes oil...
on second thought, yes, i am sure.
Your assurance has come into question. There are different types of oil. Engine oil is bad for air systems, but air tool oil is good for the stop clyinder.
You don't want to add oil in a system if you have a air dryer, air dryers are a blessing and a curse on the older vehicles
Quote from: Geoff on November 11, 2017, 09:51:05 AM
Your assurance has come into question. There are different types of oil. Engine oil is bad for air systems, but air tool oil is good for the stop clyinder.
i am sure it is Geoff, but added in the wrong place and over used it ain't good for relay and other valves and components in the brake system. there isn't any rubber in an air wrench. around here more is better... often.
ps air tool is light oil, so is 3 in 1 and some gun oils... you did read where i said i take the hose off and oil the clamping cylinder... or this...
i am not sure every part of the air system likes oil...
on second thought, yes, i am sure.
but thanks for your input.
I'd stay away from 3-in-1 oil for anything of value. I used to restore antique sewing machines, and one of the '3' components in 3-in-1 oil will turn to varnish after being exposed to heat and time. Nearly every machine which encountered 3-in-1 oil in its life had to be soaked in kerosene to break the mechanism free of the varnish which formed.
Quote from: richard5933 on November 11, 2017, 01:44:20 PM
I'd stay away from 3-in-1 oil for anything of value. I used to restore antique sewing machines, and one of the '3' components in 3-in-1 oil will turn to varnish after being exposed to heat and time. Nearly every machine which encountered 3-in-1 oil in its life had to be soaked in kerosene to break the mechanism free of the varnish which formed.
i'm talking about a clamping cylinder...it will exhaust whatever oil you put in it. the tolerances are not sewing machine close clearances.
but, good to know
;D
Air tool oil is just straight mineral oil with no paraffin wax to allow any build up that is all I have ever used lol works good on sewing machines too
If adding an oiler to the air system was needed...
Wouldn't we already have one? he asks rhetorically...
Shutters and that's it.
If there is an offending accessory device, and you've decided that a shot of lube is the solution, understanding how oil and rubber may not like one another... do as eagle19952 suggests, loosen the air line to that device, give it a drink, close up the connection, and blow away.
Please, do NOT oil the internals of any brake related devices, for sure, no exceptions. Having the rubber seal in one of those swell and stick at the wrong time, in the wrong position... dragging brakes burn down buses...
happy coaching!
buswarrior
Not sure why this thread morphed into an oil-in-the-air-system debate. The problem is not related to the air system. It's all about the fuel rack shut-off lever sticking. The OP even said that in the third post.
But, maybe we can discuss the DD3 brake chamber parking mechanism next! ::)
Quote from: gumpy on November 15, 2017, 07:18:12 AM
Not sure why this thread morphed into an oil-in-the-air-system debate. The problem is not related to the air system. It's all about the fuel rack shut-off lever sticking. The OP even said that in the third post.
But, maybe we can discuss the DD3 brake chamber parking mechanism next! ::)
I quit using those old antique DD3's and updated to the new and improved DD7's!
;D BK ;D
Once again it was me, the newbie here causing trouble :-) I had a sticky shut off solenoid too.
Quote from: neoneddy on November 15, 2017, 09:42:43 AM
Once again it was me, the newbie here causing trouble :-) I had a sticky shut off solenoid too.
You are ok no harm no fowl it happens and somebody is going to answer you so ask
Quote from: neoneddy on November 15, 2017, 09:42:43 AM
Once again it was me, the newbie here causing trouble :-) I had a sticky shut off solenoid too.
Not sure why this thread morphed into an oil-in-the-air-system debate.
So Gumpy could get his dig in.. :)
i found the problem... 2 problems actually. The cylinder was a little sticky, and oil resolved that; also, some of the exhaust pipe insulation had deteriorated /shifted and was blocking the shutdown lever. If I moved the insulation the shutdown would work. Once I oiled the cylinder the shutdown would work without moving the insulation. The pain was I had to drain the coolant and remove the coolant pipe to see what was happening. All fixed now. Thanks for all the help!
TOM
Just be sure to bleed the air out of the coolant system before any long trips. Most MCI's have bleeder valves on both front and rear cross over tubes on the engine.
short trips and keeping the coolant full will do the same thing if you don't have the bleeders.
;D BK ;D
On my old MCI 9 mechanical 6v92 we had the same issue. That level seizes up and we had to manually put it back in the run position every time I shut it down so it would be ready to start again. Dealt with this for a year before finally just taking the casing apart, pulling the washers putting new ones in, cleaning up the lever shaft, lubing it and reinstalling.
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